# Problem in understanding self-inductance

1. Nov 22, 2015

### anachin6000

In the photo I uploaded is the beginning of a study of inductors in circuits. They explain there why Ec must have the same value as En, but I don't get it:

If the total electric field inside the conductor is 0, then there should be no current in the conductor (because there is nothing which moves the charges). But the resistance is negligible (very close to 0), so the current should have an enormous value (because outside the coil we hare the generator that provides a emf). And also if the current inside the coil is 0, how is possible to have an induced emf.

Can someone explain what is wrong in my thinking (because I doubt that the book is wrong) and eventually explain this thing better?

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2. Nov 22, 2015

### davenn

did you not note the sentence after the Ec +En = zero ?
even tho the total electric field within the coil is zero, even tho Ec and En are individually non-zero. The fact that Ec is non-zero,
means there is an electric field present that will cause charges to move

Only in an idea condition would the current be infinite, in real life, as with the battery supply they have stated, the batteries have internal resistance
and this limits the maximum possible amplitude of the current flow

not sure of that helps ?

cheers
Dave

Last edited: Nov 23, 2015